Bayer's regorafenib has demonstrated it can improve progression free survival in patients with metastatic and/or unresectable gastrointestinal stromal tumours (GIST) for whom current standard treatments have become ineffective.
The German company said the phase III GRID trial, involving 199 patients whose disease had progressed despite treatment with Novartis' Glivec (imatinib) and Pfizer's Sutent (sunitinib), met its primary endpoint, although detailed results would not be available until later.
The results were positive enough for Bayer to say it "plans to submit regorafenib for marketing authorisation in the treatment of metastatic and/or unresectable GIST based on these data".
If approved, regorafenib would provide another option to treat the cancer for which Glivec and Sutent are the only current approved treatments. The drugs, which work by inhibiting the KIT and PDGFR-a mutated receptor molecules that lead to GIST, can become ineffective when other mutations occur in the receptors.
Regorafenib is developed to inhibit the functions of several enzymes involved in the development of tumours, including KIT and PDGFR.
Novartis had attempted to position Tasigna (nilotinib) as a follow-up to Glivec, but phase III interim data on the drug's use in GIST suggested it was unlikely to show superiority over its predecessor.
“Additional treatment options are needed for GIST patients after failure of approved drugs,” said Kemal Malik, head of global development and member of the Bayer HealthCare executive committee.
“These findings may represent important progress in this difficult-to-treat disease with high unmet patient need.”
Regorafenib was given orphan status by the US Food and Drug Adminsitration (FDA) in recognition of the current unmet need in treatment options for GIST, which is estimated to be diagnosed in 4,500-6,000 patients a year in the US.
Bayer has high hopes for regorafenib, which is also currently being investigated for use in colorectal cancer and the drug was named as one of four products in Bayer's pipeline with the potential to break annual revenues of €1bn if approved.